SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '40a267dc5d2680bdd8954d2905dadf58b0b1ccace8e47c032e11945679dcb409' 
  AND token = '70Jhs5YMb38jB5jSQEbSa9qZh+F+hAK3mtwNzMyLzEI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}